| A&A special issue: The CoRoT space mission: early results (22 October 2009) |
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A&A press release Released on October 22nd, 2009
Table of contents of the special issue Astronomy & Astrophysics, volume 506 N°1, October IV 2009
This week, Astronomy & Astrophysics
is publishing a special issue devoted to the early results obtained
with the CoRoT space mission. It includes 55 articles dealing with the
primary goals of the CoRoT mission, that is, exoplanet hunting and
asteroseismology, and also with other topics in stellar physics.
Up to now, seven exoplanets have been discovered in the CoRoT data and confirmed by ground-based follow-up campaigns. The difficulty with this exoplanet hunting is nicely illustrated by some papers (Moutou et al., Almenara et al.) that describe the long process of deciphering the candidates and finally characterizing a few stars hosting planets among tens of thousands. In this issue, two papers are devoted to the most exciting, and now famous, planet-hosting star: CoRoT-7. Léger et al. report the discovery of CoRoT-7b, the smallest exoplanet ever found, as was announced in February 2009 during the first CoRoT international symposium. In a second article, Queloz et al. measured the mass of the planet (5 Earth masses), using additional, ground-based measurements. They calculated its density (about 5,6 g/cm3), showing that CoRoT-7b is a rocky planet, just like the Earth. This is the first rocky exoplanet confirmed to date. Queloz et al. also discovered a second planet in the CoRoT-7 system. Now known as CoRoT-7c, it is another super-Earth exoplanet of about 8 Earth masses.
The accuracy of the CoRoT data is exemplified by detection of the
secondary transit of CoRoT-1b, when the planet passes behind its star.
This is a real challenge because the amplitude of such an event is
about one hundred parts per million. Comparing the depths of both
transits provides information on the albedo of the planet, hence on the
nature of its atmosphere (Alonso
et al.).
Fig. 1 - Left panel: The CoRoT satellite during the last phases of its integration at Thales-Alenia Space (Cannes, France). Right upper panel: The 153 transits of CoRoT-7. Right lower panel: The oscillation spectrum of the solar-like star HD 181420. The CoRoT satellite has been orbiting the Earth for nearly three years and will be operated until 2013. This A&A special issue nicely shows that it has already been a pioneering mission and has led to major insights in both exoplanetary and asteroseismic domains. CoRoT's successors are already on their way: the NASA Kepler mission, a super CoRoT devoted to finding Earth-size and smaller exoplanets, was launched in March 2009. Even more ambitious, the ESA project PLATO is still under assessment as a part of the ESA Cosmic Vision program for 2015-2025. PLATO will be able to combine the detailed study of the stellar interior and of the planetary environment of tens of thousands of bright stars. [1] The CoRoT space mission was developed and is operated by the French space agency CNES, with participation of ESA's RSSD and science programs, Austria, Belgium, Brazil, Germany, and Spain. [2] A Be star is a B-type star that shows hydrogen emission lines. The B spectral type includes luminous, white-blue stars, with a surface temperature between 10 000 and 30 000°C. Typical Be stars are rapidly rotating, variable stars. Achernar (a Eridani) is a famous Be star. Astronomy & Astrophysics special issue: the CoRoT space mission: early results, volume 506 n°1, October IV 2009 Table of contents of the A&A special issue (free access) Contacts:
Dr. Conny Aerts Dr. Tristan Guillot
© Astronomy & Astrophysics 2009 |
